From the PuitosoPpHicaL MaaazinF, vol. xi. Suppl. February 1931. 
The Stability of Motion of Rectilinear Vortices in Ring 
Formation. By T. H. Havetocs, F.R.S. 
Introduction and Summary. 
1. ee stability of the two-dimensional motion of an 
infinite system of vortices arranged in a single row, 
or in double rows has been worked out in detail in recent 
years, but not much attention has been given to cases in 
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